From our discussion last Friday about Kanban, it seems the metric is how full the "up next" queue is. That's the purpose of the planning meeting is to keep work queued up for the dev team. If the WIP limit on "up next" is 4, how often do we have less than 4 tickets in that queue? I'm not sure how to best express that. Empty slot days per week? So if we only have 3 in that queue all week then we'd have 5 empty slot days that week.

Maybe what we care about is how often that queue gets to zero and how long it stays there. In the above example, keeping the "up next" queue at 3 every day may be better than keeping it at 4 every day. But if we're at zero for more than a day that's lack of engagement?

I'd like to discuss this rather than write about it.